“We’re incredibly excited to announce that we’ll be doing another crossover event this fall on the CW, and we’ll be introducing a new character,” Amell said. “For the very first time appearing, we’ll be fighting alongside Batwoman, which is terrific. The crossover is going to make it to air in December. I need to leave right now and start filming it.”

Along with Batwoman, the Arrowverse will also be adding Gotham City to the mix.

“We are adding the city of Gotham into the Arrowverse,” Mark Pedowitz, President of The CW, added. “This will be another full-throttled action packed event.”

“No, I love a good Easter egg,” he told ComicBook.com, “and I love doing the occasional name drop. You know, we name-dropped Hal Jordan at the beginning of Season 3, but it’s really just fun for us. I think in the Arrowverse we have our own Justice League, and the Green Lantern, Wonder Woman, Batman … these are all characters that are either spoken for on the movie side and/or other shows. There’s a Bruce Wayne on Gotham.”

It appears the network has decided instead of trying to fit Batman in the Arrowverse, the next best thing is including a member of his crime-fighting family. The question remains whether Batwoman will reside on Earth-1 with The Flash and Green Arrow, or call Supergirl's Earth-2 home.

Last year's Arrowverse crossover between Supergirl, The Flash, Arrow and DC's Legends of Tomorrow saw the superheroes take on evil Nazis from another Earth.